1. Field of the Invention
This invention relates to wheel drive mechanisms located at the outer ends of drive axles and more particularly to such mechanisms which can be disconnected or shifted to a different ratio.
2. Description of the Prior Art
In some uses of axles with gear drive mechanisms at the outer ends, particularly in heavy duty applications, it is desirable to be able to disconnect the drive mechanism or shift it to a different ratio. U.S. Pat. No. 3,184,985 Dreitzler affords a discussion of the circumstances when disconnection may be desirable and discloses a mechanism whereby disconnection may be achieved. However, the mechanism of the Dreitzler patent requires that the operator of the vehicle leave the operator's station and manually disconnect each wheel drive mecahnism at the wheel.
The present invention deals with the same problems but provides that the operator can disconnect the drive mechanisms at two or more wheels of a vehicle, or shift them to a different ratio, without leaving the operator's station.
U.S. Pat. No. 3,426,620 Pleska discloses a wheel drive comprising a pair of gear sets housed in a rotary wheel hub. The gear sets cooperatively provide one speed reduction drive and one gear set provides another speed reduction drive having less speed reduction with both drives established by clutch engagement accomplished by movement of an annular gear member of one of the gear sets. A neutral or non-drive position is also provided.
U.S. Pat. No. 1,370,373 Starr discloses a wheel drive mechanism wherein three choices are provided, that is, a gear reduction drive, direct drive and a neutral or non-drive position. One of the three choices is selected by moving the axle shaft axially.